Stop mechanism



No. 6217-, 2'4L. Paxt elnmtt liwne; 20, I899.

W. STEVENS.

STOP MECHANISM.

(Application filed Dec. 28, 1897.)

(N0: Mimdleli.)

I INVENTUR- ATT'Y.

NlTED STATES ATENT OFFICE.

WILLIAM STEVENS, OF BRAINTREE, MASSACHUSETTS, ASSIGNOR OF ONE- I-IALF TO WINFIELD S. BELL, OF. PITTSBURG, PENNSYLVANIA.

sro MECHANISM.

SPECIFICATION forming part'of Letters Patent No. 627,241 dated. June 20, 1899.

Application filed December 28, 1897. Serial No. 66 3,819. (No model.)

To all whom it may concern:

Be it known that LWILLIAM STEVENS, a citizen of the United States, residing in Brain.- tree, in the county of Norfolk and State of Massachusetts, have invented an Improvement in Stop Mechanism, of which the following description, in connection with the accompanying drawings, is a specification, like letters and figures on the drawings repro resenting like parts.

This invention relates to an intermittent mechanical movement or stop mechanism and is herein shown as embodied in a camera or projector, in which apparatus it is esper5 cially applicable for producing an intermittent feed of the picture-film, so that a prolonged stay or exposure of the picture and a quick withdrawal of the same may be obtained to thereby stop vibration on the screen 7 upon which the picture is projected and which is painful to the eyes and also to avoid the rain effect now commonly produced on the said screens. This result is obtained by a novel construction of feed-movement for the picture-film, as will be described.

Figure 1 is a vertical section of one form of camera or projector embodying this invention, the section being taken on the line 1 1, Fig. 2, looking toward the'right; Fig.2, a

Fig. ion the irregular line 2 2; Fig. 3, a detail of the feed-movement to be referred to; Fig. 4, a section on the line 4 4, Fig. 3, look-, ing toward the left, showing the parts in the position they occupy when the feed is about to take place; Fig. 5, a view similar to Fig;

4, showing the parts in the position they occupy during the progress of the feed; Figs. 6 and 7, details to be referred to.

The movement which forms the essential transverse section. of the projector shown in ing a feature of this invention and which is here-- row 20.

ing a rentrant portion a which imparts to the said journal approximately the form ofa crescent, as shown in Figs. 4 and 5. The driven member consists of a substantially canoe-shaped body or piece a", preferably of metal and having its opposite faces 2 3 made in arcs of the same circlenamely, that of the circularopening a in the member a-the member at having its center Within the opening a and adjacent to the circumference of the circular opening a, and in order to permit the canoe-shaped member a. to turn on its center the member Ct is provided with a recess or openinga having one of its walls a made in the arc of a circle which is substantially the same as the circular sides 2 3 of the driven member a, for a purpose as will be described. i

The driven member (LG is provided withlugs or projecting arms a a, extended from. its upper face substantially at right angles to the length of said member, and the said arms are adapted to be engaged by a pin stud, or projection e on the driving member a once for every revolution of said driving member. The rotary movement of the driven member a is permitted by the opening a in the driving member, which opening may and preferably will be of a width equal to about oneninth of the circumference of the circular opening a in the driving member, so that for eight-ninths of the circumference of said opening the driven member a is locked against rotation. The driven member o is turned onehalt a revolution for each complete revolution of the driving member by the engagement of the pin or projection a with one of the arms (r (0 and by the end wall (t of the open- Referring to Fig. 4, the pin or projection 00 is shown as about to engage the arm c4 of the driven member, the driving member a moving in the direction indicated by the ar- As the driving member a is moved 5 in the direction indicated by the arrow 20 its I pin or projection (L13 engages the arm a and turns the member a about its center and removes one circular side, as 2, from engagement with the circumferential wall of the cir- I03 cular opening a, bringing one pointed end of the member a into the opening a as represented in Fig. 5, and at or about the time the pin or projection a passes by or out of engagement with the arm a, the curved end wall a of the opening a engages the opposite circular-side 3 of the driven member and continues the rotary movement of the driven member until it has turned the latter onehalf a revolution, at which time the circular side 3 of the driven member is brought into engagement with the circumferential wall of the opening a and the driven memberis thereby locked against rotary movement until the driving member has completed one revolution, and on the second revolution of the driving member the driven member is given another half-rotation by the pin a and wall a of the opening a engaging the other arm a of the driven member.

The mechanical movement herein described is especially advantageous for use with cameras orprojectors as a feed-movement for the film, and in Figs. 1 and 2 I have shown the same adapted to a camera or projector consisting of a box or casing 19, which contains two reels 6' 5 mounted in suitable bearings in a framework 19*, attached to a base 19 which lattersupports uprights b 6 1%. (See Fig. 2. The upright 1) supports in suitable bearings a rotar shaft b rovided as shown, with a driving-pulley Z2 and with a disk D to which the driving member a is suitably attached to revolve therewith about the segmental journal a secured to or forming part of the upright If. The upright b forms a bearing for one end of the shaft or pivot 4 for the driven member (t the other end of said shaft being journaled in the upright 5 The shaft has secured to it, so as to form practicallya part thereof, a sleeve or hub 11 having at its opposite ends nubs or projections b which form practically the teeth of a sprocket-wheel and which are designed in practice to engage suitable holes or perforations at the opposite sides of the picture-film. (Not herein shown, but-which may be supposed to be drawn off from the reel 1) and Wound upon the reel If.) The feed-roll or sprocket 6 has cooperating with it, as herein shown, suitable springpressed rolls 19 which hold the picture-film in engagement with the feed-roll.

The picture-film is fed past an opening 19 in a lens-box Z1 containing suitable lenses 1) b and is supported above the said lensbox by a sprocket-roll I), with which cooperate spring-actuated rolls Z1 The sprocket-roll b is rotated in the same direction as the feed-roll or sprocket 12 by a gear 6 on the driving-shaft meshing with an interme- In practice the driving-shaft b is designed to be revolved at a high rate of speed, and consequently it will be seen that the period of movement for the film, which is preferably about one-ninth the time it takes the shaft b to make one revolution, is substantially negligible, and as aresult the pictures projected on the screen are practically stationary and the rain effect or vibration on the screen is obviated and the painful and injurious effect on the eyes of the spectator is avoided, as the movementof the picture-film across is imperceptible.

I claim-- 1. A stop mechanism, comprising a rotatable drivingmember having a circular opening to fit and turn upon a segmental journal or boss, and provided with an opening a and with a projection adjacent to the opening a and a rotatable driven member consisting of a canoe-shaped body having circular sides 2, 3, of substantially the same are as the circumferential wall of the circular opening in the driving member, and provided with projecting arms which are engaged by the projection on the driving member to turn the canoe-shaped body into the opening a,

v substantially as and for the purpose specified.

2. A stop mechanism, comprising a rotatable driving member having a circular opening provided with a smooth circumferential wall, and a rotatable driven member located Within the said circular opening and having arc-shaped facesofthe same radius as the circular opening to engage said circumferential wall and actuated by the driving mem 'berto make one-half a revolution'while the driving member is making a part of one revolution, and to remain locked for the remaining portion of the revolution of the driving member, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WILLIAM STEVENS.

Witnesses:

. JAs.,I-I. OHUROHiLL,

J .YMURPHY.

IIO 

